The Schenectady County district attorney has yet to convene a grand jury, 16 months after the police killed a man.

THE STAKES:

How much longer will the mother of the victim continue to believe in the system?

Listen to the reasonable request, and the understandable suspicion, of a grieving mother: "I just want to find out everything that happened, and the longer it takes, the more it makes me think they might be hiding something."

That was Yvette Cedres last month, almost 15 months after her 43-year-old son Luis Rivera was shot to death by the Schenectady police.

Here she is now, only mildly appeased as she responds to the autopsy report that she fought for more than a year to obtain:

"It confirms to me he was shot twice, that's clear to me; but I still have questions about if he was running when they shot, and that's why I want to see the video," Ms. Cedres says. "My belief is he was shot in the back while he was running for his life."

Quite an accusation, one that cries out for a response.

So why can't the people empowered to respond to it — to either vindicate an anguished mother, or else conclude that for all her pain, her conclusions are off base — show more of a sense of urgency?

That means, most of all, Schenectady County District Attorney Robert Carney. His repeated promises to convene a grand jury investigation into Mr. Rivera's death are wearing thin. His explanation that his office is overwhelmed with high-profile cases doesn't cut it.

A prosecutor's office that was quick to disclose that a 9mm semiautomatic pistol was found near Mr. Rivera's body — evidence that might support the police contention that the three officers who fired 14 shots at him were acting in self-defense — owes the public a full and official account of just what happened on Aug. 12, 2011.

Authorities also had no problem putting out the word that Mr. Rivera had a criminal history that included a conviction for an illegal gun offense. That's relevant, up to a point. But such information becomes less and less useful the longer the other details of Mr. Rivera's life, and death, remain the agonizing matter of unanswered questions.

What's most surprising is how much confidence Ms. Cedres has in the criminal justice system after all her dealings with it.

"I'm not hating on cops in Schenectady, and I'm not saying anything that my son did or didn't do," she says. "I just want to see the proof. Nothing is going to bring my son back. I just want to know the truth."

Translation, to use a legal maxim: Justice delayed is justice denied.

Justice also demands more than speculation, from either Ms. Cedres or Schenectady Police Chief Mark Chaires.

"I think it's an unfortunate set of circumstances that led to his shooting," Mr. Chaires.

That much is obvious when a man is dead, especially under circumstances like these. The police have, in their own view, essentially vindicated themselves, based largely on the video that Ms. Cedres hasn't been allowed to see. The dead man's mother has yet to be dissuaded from believing that he was running for his life when he was struck by one bullet and then another. Other witnesses have said that Mr. Rivera was handcuffed when he was shot.

It's up to a grand jury to determine precisely what misfortune took the life of Mr. Rivera. And it's up to the district attorney to convene that grand jury. Critical work in both cases.